Internal-combustion engine.



UNETED STS T QFFQ.

HERBERT II. Dow, OFMIDLAND, MICHIGAN, AssIeNoR To THR irns'rINeHoUsn MACHINE COMPANY, A CORPORATION or PENNSYLVANIA.

INTRRNAL-COMBUSTION ENGINE.-

'Specification of Letters Patent.

Patented Apg. 10, 1909.

pressed combustible mixture from the engine cylinder, compressing it to the point oi ignition and discharging the burning gases into' the compressed charge 1n the gas engine (X571.- inder and thereby igniting it.

The drawings accompanying this application and forming a part thereof are only illustrative,and `I desire it to be understood that the invention may be carried out by other means or a paratus than those shown or described, andll specilic construction or to any form' of'apparatus. f,

Figurel is a partial section of a cylinder of an internal combustion engine provided with apparatus for "carrying out my invention. Figs. 2 and 3 are operating cams included in the apparatus illustrated in Fig. 1.

An engine cylinder 2 is provided with a n piston 3, suitably valved discharge ports 4 and an admission port 5, which is provided with suitable valves (not shown). An auX- iliary cylinder 6 is formed in the walls 7 of the engine cylinder and is provided with a' piston 8 which is provided with packing rings!) or other suitable ymeans for maintaining a Huid-tight working fit between it and the cylinder walls. A valve 10 controls the opening between the engine cylinder 2 and the cylinder 6 and is provided with a suitable valve seat 11, arranged to insure a Huid-tight lit when the valve is closed. A valve stem 12v isrigidly secured to the valve 10 and entends centrally through the piston 8, suitable means being used for maintaining a luidtight working lit. 12 is provided with a spring pocket 13, between which and a spring yseat 14, formed integrally with'the walls 7 of theeylinder, a'

helical spring 15is located. .y y.The position of the mirino' nncketl is rendered adiustable HDOW, a

As the piston 3 do not limit myself to any i The end of the valve stem.

along the Avalve stem12 by means oi a nut 16. The spring 15 operates to hold the valve 1 0 against its scat and thereby close the opening between the cylinders 6 and 2. A pivoter-l lever 17, which reciprocates the valve 10 through the agency of the valve stem 12, is

.provided at one end with a roller 18 which contacts with a cam 19. A pivoted lever/21 is connected at oneI end `with the piston 8 .and at the other is provided with a roller 22 which contacts with a cam 23. The cams 19 and 23, While shown on diiferent lay shafts 'or the purpose of clearness, may be located on the saine shaft and are driven at half the speed of the engine shaft byany suitable means. The cam 1 9 has a cam surface 24, which moves the lever 17 to open the valve i() and the cam 23 has a cam surface 25,

f which recprocates the piston 8 in the cylinder 6.

The operation oi the engine is as follows: oi' the gas engine cylinder discharges the burned gases from. the cylinder L) the .valve 10 is moved by the cam surface J4 to open thc port between the cylinders 2 and 6 and which remains open until after the beginning oi' the compression stroke of the piston 3. .The cam permits `the piston 8 to move to d'raw a fresh charge into the auxiliary cylinder 6 during the suction or admission stroke oll the piston. 3. Ai'ter compression starts in the cylinder 2 the cam surface 24 of the cam 19 is moved to such a position that the spring 15 operates to close the valve 10 and confine a partially lcompressed charge in the cylinder 6. As soon as the valve 10 is closed, the cam surface 25 moves the piston 8 to compress the confined charge in the cylinder 6. The cam surface 25 is so arranged that sufficient pressure is attained in the auX- iliary cylinder 6 to ire the coniined charge at about the time of maximum compression in 6 until alter the beginning of the suction stroke oi' the piston 3 and then, while the admission valve of the engine `and the valve 10 are still open, it moves backJ into the cylvinder 6 and draws a portion of the fresh chargefrom the gas engine cylinder 2. The

charge in the cylinder 6.is subjected to the increasing pressure of the engine vcylinder 2 until the valve 10 is closed, and from that point compression is carried forward by the downward movement of the piston 8.

While the spring 15 is designed to permit the valve y10 to open under the pressure occasioned by the explosion in the cylinder 6, it must be of sufficient strength to resist the pressure in the cylinder 6 up to the point of ignition., Since .the valve v is subjected to high pressure `on each side, the spring Will only have to be strong enoughto overcome the difference in pressure existinflr between the cylinder 6 and the cylinder 2 lbefore the explosion takes place in 'the lcylinder 6. The

time of ignition in the-cylinder 6 .can be ad 4 justed by varying the position of the cam .surface 25 or by varying the throw of the 'pist-on 8. The tension ofthe spring 15 can e varied by changing the position ofthe spring pocket -13 by adjusting the nut 16.

, It is apparent that this method of ignition may be` used in various types of gas enginesv and with values.

lVhat I claim is:

' 1. In combination with a cylinder of a gas gaseswith widely .varying thermal engine, an auxiliary cylinder communicating therewith, an auxiliary piston located within said cylinder, a valve controlling communication between said cylinders, a cam for reciprocating said auxiliary piston to draw al portion of the compressed charge of the egine cylinder into the auxiliary cylinder and to compress saidchargeto the point of ignition, a cam `for reciprocating said valve to open and close eommunicationbetween said cylinders, and means auxiliary to said cam forA permitting said valve to' open in response to an expansion pressure within said cylmder.

2. In combination with a cylinder of a gas engine, an auxiliary cylinder communicating ltherewith, an auxiliary piston located within August, 1906.

' HERBERT H. DOW. Witnesses:

Tiros. GRIsWoLD, Jr.,. JAMES C. GRAVES. 

